<template>
  <div :style="{ padding: '0 0 32px 32px' }">
    <h4 :style="{ marginBottom: '20px' }">{{ title }}</h4>
    <v-chart :data="data" :force-fit="true" :height="height" :onClick="handleClick" :scale="scale">
      <v-tooltip/>
      <v-axis/>
      <v-legend/>
      <v-bar :adjust="adjust" color="type" position="x*y"/>
    </v-chart>
  </div>
</template>

<script>
import {DataSet} from '@antv/data-set'
import {ChartEventMixins} from './mixins/ChartMixins'

export default {
  name: 'BarMultid',
  mixins: [ChartEventMixins],
  props: {
    title: {
      type: String,
      default: ''
    },
    dataSource: {
      type: Array,
      default: () => [
        {
          type: 'Jeecg',
          'Jan.': 18.9,
          'Feb.': 28.8,
          'Mar.': 39.3,
          'Apr.': 81.4,
          'May': 47,
          'Jun.': 20.3,
          'Jul.': 24,
          'Aug.': 35.6
        },
        {
          type: 'Jeebt',
          'Jan.': 12.4,
          'Feb.': 23.2,
          'Mar.': 34.5,
          'Apr.': 99.7,
          'May': 52.6,
          'Jun.': 35.5,
          'Jul.': 37.4,
          'Aug.': 42.4
        }
      ]
    },
    fields: {
      type: Array,
      default: () => ['Jan.', 'Feb.', 'Mar.', 'Apr.', 'May', 'Jun.', 'Jul.', 'Aug.']
    },
    // 别名，需要的格式：[{field:'name',alias:'姓名'}, {field:'sex',alias:'性别'}]
    aliases: {
      type: Array,
      default: () => []
    },
    height: {
      type: Number,
      default: 254
    }
  },
  data() {
    return {
      adjust: [{
        type: 'dodge',
        marginRatio: 1 / 32
      }]
    }
  },
  computed: {
    data() {
      const dv = new DataSet.View().source(this.dataSource)
      dv.transform({
        type: 'fold',
        fields: this.fields,
        key: 'x',
        value: 'y'
      })

      // bar 使用不了 - 和 / 所以替换下
      let rows = dv.rows.map(row => {
        if (typeof row.x === 'string') {
          row.x = row.x.replace(/[-/]/g, '_')
        }
        return row
      })
      // 替换别名
      rows.forEach(row => {
        for (let item of this.aliases) {
          if (item.field === row.type) {
            row.type = item.alias
            break
          }
        }
      })
      return rows
    },
    scale() {
      return [
        {
          type: 'cat',
          dataKey: 'x'
        }
      ]
    }
  }
}
</script>

<style scoped>

</style>